EP3756842A1 - Kiss-cut draw knife - Google Patents

Abstract

The invention relates to a cutting machine knife for use in a cutting tool of a cutting machine, designed and precisely provided for kiss-cut cutting a sticker adhering to a sticker carrier, the sticker carrier having a carrier layer and an adhesion-reducing layer, the sticker having a cover layer and an adhesive layer , wherein the adhesive layer adheres releasably to the adhesion-reducing layer, wherein the cutting machine knife is provided for use in the context of an automatic kiss-cut cutting mode, in which the cutting machine knife is guided by the cutting machine in a cutting direction along the sticker and the sticker whole and the Sticker carrier not or only partially severed, the cutting machine knife having the following: a holding section for inserting the cutting machine knife into a knife holder of the cutting tool, a length at right angles to the cutting direction gsachse, a blade with a cutting edge and a back, the cutting edge, when viewed in a plane that is spanned by the cutting direction and the longitudinal axis, encloses a first angle with the cutting direction which is less than 90 °, and one between the Cut and the intermediate zone located on the back, which, again when viewed in said plane, includes a second angle with the cutting direction, which is between 130 ° and 170 °.

Description

FIELD OF THE INVENTION

The present invention relates to a cutting machine knife which is designed and precisely provided for kiss-cut cutting or through-cut cutting of stickers.

BACKGROUND OF THE INVENTION

For such a cutting of stickers, cutting machines are used which provide a kiss-cut cutting mode and a through-cut cutting mode and in whose cutting tool the cutting machine knife according to the invention is used.

In kiss-cut cutting, an upper side, i.e. the sticker itself, must be cut through so that it can be removed in the desired shape. Here, a bottom side remains, i.e. the carrier layer to which the sticker adheres is intact or is only slightly grooved, scratched or cut. For easier removal, the carrier layer is usually provided with an adhesion-reducing coating, the sticker, which has a special adhesive layer, being releasably adhered to this adhesion-reducing coating.

With through-cut cutting, both sides - the sticker and the carrier layer - should be cut, as it is desirable that the sticker as a whole (i.e. with the carrier layer) already shows its shape. To make it easier to remove the sticker, an additional flap can also be cut out, with a small kiss-cut cut usually being made here at the transition between the flap and the sticker so that the flap is not part of the sticker.

For a perfect cutting result there are special requirements for the knives used in the mentioned cutting modes. Cutting machine knives are known from the prior art, which have a pointed or have a blade tip parallel to the cutting direction. Such knives are not optimal for the cutting process and have a limited service life, since their blade tips tend to wear out early on.

OBJECT OF THE INVENTION

It is therefore an object of the invention to provide an improved cutting machine knife of the generic type for kiss-cut cutting and through-cut cutting. The cutting machine knife according to the invention is significantly less susceptible to wear due to its design, thus enables a more stable cutting process and offers a longer service life with constant cutting precision.

SUMMARY OF THE INVENTION

The invention relates to a cutting machine knife for use in a cutting tool of a cutting machine, designed and precisely provided for cutting a sticker in a kiss-cut cutting mode of the cutting machine, in particular in addition to cutting the sticker in a through-cut cutting mode of the cutting machine, the sticker has a cover layer and an adhesive layer, the sticker carrier having an adhesion-reducing layer and a carrier layer, the adhesive layer being releasably adhered to the adhesion-reducing layer, the cutting machine knife being automatically guided by the cutting machine in a cutting direction along the sticker as part of the kiss-cut cutting mode and thereby not or only partially severed the sticker and the sticker carrier, possibly in the context of the through-cut cutting mode, the cutting machine knife by the cutting machine automatically in a cutting direction along the sticker bers is guided and thereby completely severed the sticker and the sticker carrier, wherein the cutting machine knife has the following: has a holding section for inserting the cutting machine knife in a knife holder of the cutting tool, one for the cutting direction Right-angled longitudinal axis, a blade with a cutting edge and a back, the cutting edge, when viewed in a plane spanned by the cutting direction and the longitudinal axis, enclosing a first angle with the cutting direction which is less than 90 °, and one between The intermediate zone located between the cutting edge and the back, which, again when viewed in said plane, encloses a second angle with the cutting direction which is between 130 ° and 170 °.

In one embodiment, the second angle is between 140 ° and 160 °, in particular 150 °.

In a further embodiment, the first angle is less than 70 °, in particular between 20 ° and 65 °, in particular 35 °, 45 ° or 60 °.

The blade between the cutting edge and the intermediate zone preferably has a point that is pointed or rounded, in particular the cutting edge and the intermediate zone encompassing a third angle that results from subtracting the second angle from the first angle.

The blade can taper towards the tip along the longitudinal axis and in relation to an axis that is perpendicular to the longitudinal axis and the cutting direction, at least on one side, in particular on both sides, in particular linearly or curved concavely or convexly.

In one embodiment, a normal distance between the tip and the longitudinal axis is less than 0.04 mm, in particular 0.02 mm, in particular 0.01 mm.

The spine can taper parallel to the cutting direction and in relation to an axis that is perpendicular to the longitudinal axis and to the cutting direction, at least on one side, in particular on both sides, in particular taper linearly or in a curved concave or convex manner.

The intermediate zone in particular forms a wedge-shaped triangular surface which runs from the tip to the back.

The longitudinal axis is preferably an axis of symmetry of at least part of the cutting machine knife, in particular a central shaft, and wherein the axis of symmetry runs through the back with a tolerance of -0.01 mm to +0.01 mm, in particular wherein the back runs parallel to the longitudinal axis.

The intermediate zone can in particular have a length between tip and back which is less than 0.04 mm, in particular between 0.03 mm and 0.01 mm, in particular 0.02 mm.

At least one of: the cutting edge, the intermediate zone and the back, in particular, again when viewed in the said plane, runs linearly or curved, concave or convex.

The cutting machine knife preferably has a length of between 10 mm and 30 mm, in particular a length of less than 20 mm.

The cutting edge in particular has a depth along the longitudinal axis of between 0.5 mm and 3 mm, in particular a depth of between 1 mm and 2.6 mm.

In one embodiment, the holding section has a diameter of between 2 mm and 4 mm, in particular a diameter of 3 mm.

The invention further relates to a use of the cutting machine knife according to the description herein used in a cutting machine with a cutting tool.

The invention also relates to a cutting machine with a cutting tool, in which the cutting machine knife is used according to the description herein, the cutting machine providing a kiss-cut cutting mode or in a through-cut cutting mode, which are provided for cutting a sticker, the The sticker has a cover layer and an adhesive layer, the sticker carrier having an adhesion-reducing layer and a carrier layer, the adhesive layer being releasably adhered to the adhesion-reducing layer, with the cutting machine knife being automatically cut by the cutting machine along the sticker as part of the kiss-cut cutting mode is performed and not or only partially severed the sticker and the sticker carrier, whereby in the context of the through-cut cutting mode, the cutting machine knife is automatically guided in a cutting direction along the sticker by the cutting machine, completely severing the sticker and the sticker carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

• Figur 1 zeigt eine gattungsgemässe Schneidemaschine, für welche das erfindungsgemässe Schneidemaschinenmesser genau vorgesehen und ausgestaltet ist;
• Figur 2 zeigt eine Ausführungsform des erfindungsgemässen Schneidemaschinenmessers;
• Figur 3 zeigt die Spitze der Klinge des Schneidemaschinenmessers aus Figur 2 in einer Detailansicht, wobei der zu durchtrennende Aufkleber, der Aufkleberträger und die Schneiderichtung zu sehen sind;
• Figur 4 zeigt die Spitze der Klinge des Schneidemaschinenmessers aus Figur 2 in einer dreidimensionalen Detailansicht;
• Figur 5 zeigt den Schichtenaufbau des zu durchtrennenden Aufklebers aus Figur 3 in einer Detailansicht;
• Figuren 6 und 7 zeigen ein gattungsgemässes Schneidemaschinenmesser aus dem Stand der Technik;

Further advantages of the present invention are apparent from the detailed description and drawings.

• Figure 1 shows a cutting machine of the generic type for which the cutting machine knife according to the invention is precisely provided and configured;
• Figure 2 shows an embodiment of the cutting machine knife according to the invention;
• Figure 3 shows the tip of the blade of the cutting machine knife Figure 2 in a detailed view, the sticker to be cut, the sticker carrier and the cutting direction can be seen;
• Figure 4 shows the tip of the blade of the cutting machine knife Figure 2 in a three-dimensional detailed view;
• Figure 5 shows the layer structure of the sticker to be cut Figure 3 in a detailed view;
• Figures 6 and 7 show a generic cutting machine knife from the prior art;

DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 shows a generic cutting machine 1, which a cutting tool can move over a machine table 4 in the X and Y directions by means of a portal. The control for this is usually carried out by a control unit 2, which can be located in the cutting machine or also externally. The cutting machine knife 3 is for this trained to be used in the tool holder. The cutting machine knife 3 is pressed in a defined manner onto the object 5 to be cut with specially adjustable forces (for example via a spring force or via a servomotor). This pressure is used for so-called kiss-cut cutting, in which only an upper layer of the object 5 is completely severed and a carrier layer that carries this upper layer either remains intact or is at most minimally scratched or grooved by the knife 3.

If the defined pressing force is increased in a defined way, or a defined cutting depth is set, through-cut cutting can also advantageously be carried out with the cutting machine knife according to the invention, in which the object 5 is completely severed and the knife tip the machine table 4 only lightly touched. The machine table 4 is usually air-permeable, because the object 5 can be held on the table 4 by the force of a vacuum generated by air suction. The surface material of the table 4 can be based on polyurethane or consist of a nonwoven fabric.

The object 5 is preferably a sticker that adheres to its carrier material, or in more general terms: a material that carries one or more stickers. Typically, such stickers are self-adhesive films or paper.

A print mode is used to cut stickers (pressing on as already mentioned above). Which type of film is cut with which pressure depends on the material specifications and may have to be determined and thus defined by means of cutting tests. The cutting machine is designed to measure the pressure exerted on the material by the tip. When the defined pressure has been reached, this can optionally be signaled by a green LED.

The optimum machining depth is achieved with kiss cutting when the knife cuts through the cover layer 100, the adhesive layer 101 and part of the sticker carrier 11. This means that the adhesion-reducing layer 111 is grooved, cut or severed, and the carrier layer 110 is cut or remains intact. The components are in Figure 5 marked. This type of cut ensures that a sticker can be detached from the sticker carrier without the sticker carrier tearing. Common foil materials reach thicknesses of up to 3 mm.

With through-cutting, the optimum processing depth is reached when the knife covers all layers, i.e. the sticker 10 and the sticker carrier 11, cut through and not damage the machine table 4.

The knife can be surrounded on the cutting tool by a (e.g. cylindrical) slider which presses the object 5 to be cut against the table 4 at the cutting area. This again ensures (i.e. in addition to a possible vacuum suction function of the table 4, which securely fixes the object 5) that the cut is carried out cleanly. The use of the slider is particularly suitable for processing reflective foils.

A pressure mode can be designed in such a way that the module (cutting tool) exerts a constant pressure, adjustable between 30 and 3500 grams, on the processing material 5.

In addition to the pressure mode, there is also a so-called position mode, which is not suitable for kiss cutting, but only for through cutting, in which a cutting depth is set in a defined manner (and no pressure), which ensures that the material is completely cut through and the table is not cut. The position mode is therefore an alternative to the pressure mode for through-cutting.

The cutting machine knife 3 according to the invention is designed precisely for the kiss-cut cutting mode and the through-cut cutting mode and ensures that precise and predictive cutting results are achieved by setting defined cutting pressures or defined cutting depths. One embodiment of the invention is shown in Figures 2 and 3 to see. The semi-cylindrical holding section 6 is used for clamping in the cutting tool of the cutting machine 1 and ensures that the knife is precisely aligned. The holding section shown is not essential to the invention and further design options for a holding section are known to those skilled in the art.

Cutting machine knives are usually made from a cylindrical raw material. In the middle area of the knife 3, this cylinder is essentially still in cycle and in relation to this, a longitudinal axis L is defined for the cutting machine knife 3, which is an axis of symmetry for this middle section.

With the cutting edge 7, the cutting machine knife 3 of course first comes into contact with the object to be cut, such as the cutting direction S in FIG Figure 3 indicates. The cutting direction S is a vector which, starting from the cutting edge, points in the direction of the cutting feed. In the example of Figure 1 the tool moves relative to the table, but embodiments are also conceivable in which the table moves relative to the tool. The cutting direction S is usually perpendicular to the longitudinal axis L. A depth T of the cutting edge 7 - viewed parallel to the longitudinal axis L - is preferably between 0.5 mm and 3 mm.

The blade of the knife 3 also has a back 8, which is located facing away from the gate. According to the invention there is an angled intermediate zone 9 between the cutting edge 7 and the back 8, which in the mentioned cutting modes ensures a surprisingly high wear resistance of the knife and thus long-lasting and constant precision of the cutting results. In addition, the cutting machine knife according to the invention allows a lower piercing force and a lower cutting force (along the cutting direction) in both cutting modes compared to known knives.

The view of Figure 3 lies in a plane which is spanned by the longitudinal axis L and the cutting direction S. According to the invention, in this view, the intermediate zone 9 has an angle W2 to the longitudinal axis L of between 40 ° and 80 °. This means that there is an angle with the cutting direction S of 130 ° to 170 °. If this angle approaches the range of about 60 °

(based on L) or 150 ° (based on S) an optimum of the effects according to the invention is increasingly established. The longitudinal axis L runs in Figure 3 through the intermediate zone 9, but preferably it runs along the back 8, this with a tolerance range around the back of -0.01 mm to +0.01 mm.

When speaking of the cutting edge, the back and the intermediate zone, the edge is generally meant. These edges are preferably each straight, i.e. linear. However, in other embodiments they can also have a curve-like profile.

In the context of kiss cutting, the tip 12 of the blade protrudes “just about” into the sticker carrier 11 so that it is not damaged as far as possible, but the sticker 10 is completely severed. In this situation, load peaks arise which place special demands on the design of the cutting machine knife. Similar load peaks arise during through-cutting, in which the knife tip touches the machine table.

The intermediate zone 9, viewed normal to the longitudinal axis L or parallel to the cutting direction S, has a length Z between the tip 12 and the back 8 which is preferably less than 0.04 mm, in particular between 0.03 mm and 0.01 mm, in particular 0.02 mm .

Figure 4 shows the area A again in a three-dimensional (but not necessarily dimensionally accurate) view. Here you can see how the intermediate zone 9 forms a wedge-shaped triangular surface which runs from the tip 12 to the back 8, ie a triangle is formed through the two corners on the back 8 and the tip 12. This surface can be completely flat, or in other embodiments concave or convex. The back also preferably has a flat surface, as in FIG Figure 4 you can see. In other embodiments, as well as in the above-mentioned triangular area of the intermediate zone, this area can also assume further shapes. The cutting edge 7 is of course sharpened and is therefore a sharp edge. The sharpening can also be linear or curved (concave or convex).

Figure 5 shows again in detail the layers of the object to be cut in the side view. The sticker 10 has a cover layer 100 and an adhesive layer 101 firmly connected to the cover layer 100. With the aid of this adhesive layer 101, the sticker 10 adheres to the adhesion-reducing layer 111 of the sticker carrier 11. The adhesion-reducing layer 111 in turn is firmly connected to the carrier layer 110. The material of the adhesion-reducing layer 111 is based, for example, on silicone or a wax. The cover layer 100 and the carrier layer 110 can consist of paper and / or plastic film.

The design of the knife 3 according to the invention improves the process of cutting stickers in a very targeted manner and minimizes the wear and tear that occurs on knives of the prior art and is briefly explained below.

Figure 6 shows the structure of a generic kiss-cut knife with cutting edge 14 and back 15. Shows in detail Figure 7 the in Figure 6 tip area marked with B. Between the cutting edge 14 and the back 15 there is what is known as a flat spot 16 which, during kiss-cut cutting, also protrudes slightly into the carrier 11 and completely severed the sticker 10. The flat point 16 is provided in order to prevent a “perfect”, ie very pointed tip, breaking off.

The cutting process of such a knife 13 known from the prior art is not optimal, however, since, depending on the design of the flat point 16, the area of the knife back 15 rests on the carrier layer. This causes higher cutting forces and vibrations when cutting, which affects the cutting result. This effect also severely limits the service life. This is due to wear and tear, which is shown by first breaks 17 in the area of the flat spot 16 and second breaks 18 in the area of the back 15. The results of kiss-cut cutting and through-cut cutting therefore no longer meet the requirements relatively early on and the knife has to be replaced. In addition, the flat point 16 causes higher piercing forces, which is relevant because that Cutting machine knife in a sticker cutting process is usually often lifted and (at another point or in a different orientation) stuck in again.

The knife 3 according to the invention avoids all these signs of wear and tear and thus offers a significantly better cutting quality and an increased service life.

While the invention has been illustrated in terms of its preferred embodiment (s), many other changes and variations can be made without departing from the scope of the present invention. Therefore, it is intended that the appended claims cover changes and variations that come within the true scope of the invention.

Claims (15)

Cutting machine knife (3) for use in a cutting tool of a cutting machine (1), designed and precisely provided for cutting a sticker (10) in a kiss-cut cutting mode of the cutting machine, in particular in addition to cutting the sticker in a through-cut cutting mode Cutting machine,
wherein the sticker has a cover layer (100) and an adhesive layer (101),
wherein the sticker carrier has an adhesion-reducing layer (111) and a carrier layer (110),
the adhesive layer adhering releasably to the adhesion-reducing layer,
in the context of the kiss-cut cutting mode, the cutting machine knife is automatically guided by the cutting machine in a cutting direction (S) along the sticker and not or only partially severed the sticker and the sticker carrier, possibly in the context of the through-cut cutting mode the cutting machine knife is automatically guided by the cutting machine in a cutting direction (S) along the sticker, completely cutting through the sticker and the sticker carrier,
wherein the cutting machine knife comprises: - Has a holding section (6) for inserting the cutting machine knife into a knife holder of the cutting tool, - a longitudinal axis (L) at right angles to the cutting direction, - A blade with a cutting edge (7) and a back (8), the cutting edge, when viewed in a plane that is spanned by the cutting direction and the longitudinal axis, encloses a first angle (W1) with the cutting direction which is less than Is 90 °, marked by
an intermediate zone (9) located between the cutting edge and the back, which, again when viewed in said plane, encloses a second angle (W2) with the cutting direction which is between 130 ° and 170 °. Cutting machine knife (3) according to claim 1, wherein the second angle (W2) is between 140 ° and 160 °, in particular 150 °. Cutting machine knife (3) according to one of the preceding claims, wherein the first angle (W1) is less than 70 °, in particular between 20 ° and 65 °, in particular 35 °, 45 ° or 60 °. Cutting machine knife (3) according to one of the preceding claims, wherein
the blade between the cutting edge (7) and the intermediate zone (9) has a point (12) which is pointed or rounded, in particular wherein the cutting edge and the intermediate zone enclose a third angle (W3) resulting from a subtraction of the second Angle (W2) from the first angle (W1) results. Cutting machine knife (3) according to claim 4, wherein the blade tapers along the longitudinal axis (L) and in relation to an axis which is perpendicular to the longitudinal axis and the cutting direction towards the tip (12) at least on one side, in particular on both sides, in particular linearly or curved concave or tapered convex. Cutting machine knife (3) according to one of Claims 4 and 5, a normal distance between the tip (12) and the longitudinal axis (L) being less than 0.04 mm, in particular 0.02 mm, in particular 0.01 mm. Cutting machine knife (3) according to one of the preceding claims, wherein the back (8) tapers parallel to the cutting direction (S) and based on an axis that is perpendicular to the longitudinal axis and to the cutting direction, at least on one side, in particular on both sides, in particular linearly or curved tapered concave or convex. Cutting machine knife (3) according to one of the preceding claims, wherein the intermediate zone (9) forms a wedge-shaped triangular surface which runs from the tip (12) to the back (8). Cutting machine knife (3) according to one of the preceding claims, wherein the longitudinal axis (L) is an axis of symmetry of at least part of the cutting machine knife, in particular a central shaft, and wherein the axis of symmetry with a tolerance of -0.01 mm to +0.01 mm through the back (8) runs, in particular wherein the back runs parallel to the longitudinal axis. Cutting machine knife (3) according to one of the preceding claims, wherein the intermediate zone (9) between tip (12) and back (8) has a length (Z) which is less than 0.04 mm, in particular between 0.03 mm and 0.01 mm, in particular 0.02 mm. Cutting machine knife (3) according to one of the preceding claims, wherein at least one of: the cutting edge (7), the intermediate zone (9) and the back (8), again when viewed in said plane, is linear or curved, concave or convex. Cutting machine knife (3) according to one of the preceding claims, wherein the cutting machine knife has a length of between 10 mm and 30 mm, in particular a length of less than 20 mm. Cutting machine knife (3) according to one of the preceding claims, wherein the cutting edge (7) has a depth (T) along the longitudinal axis (L) of between 0.5 mm and 3 mm, in particular a depth of between 1 mm and 2.6 mm. Cutting machine knife (3) according to one of the preceding claims, wherein the holding section (6) has a diameter of between 2 mm and 4 mm, in particular a diameter of 3 mm. Use of the cutting machine knife (3) according to one of Claims 1 to 14, used in a cutting machine (1) with a cutting tool.

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